Carbon-based Composite Electrodes: Preparation, Characterization and Application in Electroanalysis

Abstract: Electrodes based on carbon, i.e., expanded graphite (20%, wt.)-epoxy composite(20EG-Epoxy) and expanded graphite (20%, wt.)-polystyrene composite (20EG-PS) havebeen prepared, characterized using scanning electron microscopy (SEM) and cyclicvoltammetry (CV), and tested as anodic sensors. The electrodes exhibited good mechanicalresistance and low electrical resistances. Scan rate dependent cyclic voltammetry responsesat 20EG-Epoxy and 20EG-PS composite electrodes, which were exemplified for thiourea(TU), a toxic sulphur organic compound selected as testing target analyte in 0.1 M Na₂SO₄ supporting electrolyte, were investigated. The obtained voltammetric data were inaccordance with those for a random array of microelectrodes. The voltammetric andchronoamperometric detection results of TU in tap water samples, without a supplementaryaddition of supporting electrolyte, at 20EG-Epoxy electrode proved its use for directanalysis of environmental samples.